Maybe for BSD? They have a lot of the original code though, and BSD moves a lot slower than Linux. Modern BSDs have a lot more in common with original UNIX than macOS does, but macOS paid for the certification and the BSDs didn’t.
Linux never was UNIX though. It does loosely follow the UNIX philosophy though.
Although for both Linux and (especially) BSD, isn’t there a “Unix of Theseus” issue here, if you understand my meaning?
Maybe for BSD? They have a lot of the original code though, and BSD moves a lot slower than Linux. Modern BSDs have a lot more in common with original UNIX than macOS does, but macOS paid for the certification and the BSDs didn’t.
Linux never was UNIX though. It does loosely follow the UNIX philosophy though.